Motor operated automatic regulator



April 18, 1944. E. w. SEEGER EIAL MOTOR OPERATED AUTOMATIC REGULATOR Filed NOV. 26, 1941 Patented Apr. 18, 1944 MOTOR orsaa'ran ao'roma'rro amom'roa I Edwin W. Sceger, Wauwatosa, Jurg A. Son, Mllwaukee, and Carro Wis assignors ll Stansbury, to Cutler-Hammer, waukee, Wis., a cor-poi- Wauwatosa,

Ina, Milatlon of Delaware Application November 28, 1941, Serial No. 420,462

14 Claims.

The invention relates to motor operated automatic regulators. and while not limited thereto it is particularly adapted to regulators for illuminating systems wherein the light output of electric lamps is to be regulated in accordance with the illumination of a surface, which is subjected to illumination by a second light source of varying intensity,

An object of the invention is to provide a system of the aforementioned type which maintains the illumination of a surface at a given level, if the illumination by a second light source alone is below said level.

Another object is to provide a regulator for an artificial light source which will control the intensity of said source so as to maintain the illumination of a surface, which is simultaneously illuminated by another variable light source, at a given minimum level, unless the intensity of said other source alone results in a higher level of illumination than said minimum.

Another and more specific object is to provide an illumination control system for a classroom, auditorium, or the like, wherein a variable degree of natural light (such as daylight) is utilized to effect illumination thereof-such system affording control of an artificial source of light in such a manner as to insure maintenance of a predetermined degree of illumination in the event that the illumination afforded by the source of natural light falls below said predetermined degree or value.

Another object is to provide a regulator for an artificial light source which responds to thetotal illumination of a surface and controls said light source to prevent the total illumination from falling below a given level.

Another object is to provide a regulator of the aforementioned quick and accurate in its response.

Another object is to provide a regulator of the aforementioned type in which the energy supplied to an artificial light source is controlled by an operating mechanism which includes a reversible alternating current driving motor.

Another object of the invention is to provide a reversible controller for an illumination control system, which is quick and accurate in its response to a s table controlling influence.

Other objects and advantages will hereinafter appear.

The accompanying drawing illustrates schematically and diagrammatically a system of illumination embodying the invention, which will now be described.

In the system a bank motor operated type which is of electric lamps I may be supplied with current from the alternatin current bus bars 2 and 3 of an alternating current source of supply. A variable voltage autotransformer 4 is connected with its input terminals across the bus bars 2 and 3. It is provided with a sliding brush 5 by means of which its output voltage may be varied in a' known manner. .The'brush I is conductively connected to a bus bar 0, which is connected to one terminal of the lamps I, while their other terminal is connected to the bus :bar 3. The brush 5 is also rigidly mechanically connected with but insulated from a nut 1 which engages a threaded shaft 8 which in turn is connected to the armature of a reversible motor 8, so that upon rotation of the motor in one direction or the other,

7 5 are moved in one direction or the other to vary the voltage impressed on the lamps I.

The motor 8 has a common terminal 9, which is connected to the bus bar 3, and with reversing windings l and 8, which latter are provided with reversing terminals 9 and 9, respectively.

The motor 9 is controlled by a center-biased relay l0, comprising a lever II, which is pivoted at its center to provide for oscillatory movement thereof and which has attached to its ends the magnetic cores i2 and I3, respectively. The cores l2 and I3 cooperate with energizing coils II and I5, respectively, which are connected in series across the bus bars i6 and ll of a direct and said coils that normally their pulls balance, so that the lever its central or neutral position. Attached to the lever I l and oscillatable therewith is a contact arm l8, which is connected to one of the bus bars, 2, of the alternating current supply through an impedance 26, connected in parallel with a condenser 21. A stud or bolt I8- is fastened at its center to the arm l8 and is provided at both of its transversely projecting ends with heads or nuts, as shown, which serve as abutments to limit the degrees of outward movement of a pair of contact fingers |8 relatively to the arm l8. Springs l8, surrounding the ends of stud 18* are interposed between the fingers |8 and the arm l8 and normally bias the fingers l8 into contact with stationary contacts l9 and 20, respectively. When the lever H and arm 18 are oscillated from the center position to one side or the other, the circuit between one of the fingers 18 and the respective contact H or 20 is interrupted. The contact I9 is connected to the motor terminal 9 and the contact 20 is connected to the motor terminal 9.

The coil 14 is shunted by an adjustable resistor 21 by means of which the pull of the two coils l4 and 15 can be balanced.

The system further includes an electron tube 22, having a cathode 22", an anode 22 and a control grid 22. The anode 22 is connected to the point a: between the coils l4 and i5, and the cathode 22 is connected to an adjustable output 2 2,346,794 contact 23* or a potentiometer rheostat 23, which It will be apparent that the impedance 26 may is connected across the bus bars l8 and il. be either an ohmic resistance, or an inductance A photo-electric cell 24 which responds to the and 22.

The system described operates as follows: Ii, With the parts in the respective positions thereof shown in ing through tube 22 is of such a pull of the coils i6 and i6 balance, and the relay it) is in its center If now the degree of illumination to which 2 is subjected decreases, its resistance which increases their intensity, and thus the total illumination of the cell 24. As the illumination of cell 22 3 again becomes normal, the po= tentlal of the grid 22 the foregoing explanation.

It will be observed that the and 9" are normally connected in parallel with relay id,

as the contacts 98, 98 stationary contacts 69 and it, e motor is brought to a quick stop, and hunting thereof is prevented. By properly motor 9 when the same preselected, and the re current oi tor and its rng torque may be similarly pre= determined.

tit?

or a combination of both. "I; will also be apparent that the impedance 26 may be entirely omitted, or, if desired, the condenser 21 may be omittiled, and the motor fed through the impedance 26 a one.

The adjustment of the contact 28" varies the potential of the cathode 22 of the anode 22 lamp or lamps i.

By this arrangement, it will be apparent to those skilled in the art that when the degree of natural light is when the occasion arises.

practice source of light limit switch 28 value from When limit switch 29 lianey to zero, dependent upon the amount of daylight available, and the intensity of lllumination of the remains at zero value as long as the daylight produces at least the desired minimum illumination.

We claim:

1. A control system for controlling the light output of an electric lamp to maintain the illumination of a surface illuminated thereby and by an uncontrolled light source Jointly at a degree of illumination above a given minimum, comprising, in combination, an electric lamp, a circuit therefor, a photo-electric cell having a characteristic responsive to the degree of the total illumination of said surface, an electron tube connected to a source of energ adjustable means to effect response or said electron tube to the operation of said photo-electric cell, a relay responsive to the current of said tube, an alter,- nating current motor having a pair of reversing windings normally connected by said relay in parallel with each other and in series with an impedance across an alternating current source for stopping said motor, said relay upon response operating to disconnect one or said reversing windings from circuit to cause said motor to rotate in opposite directions selectively, and a regulator operable by said motor and adapted,to vary the voltage impressed upon the circuit of said electric lamp.

2. A control system for controllin the light output of an electric lamp to mainta the illumination of a surface illuminated thereby and by an uncontrolled light source jointly at a degree of illumination above a given minimum, comin combination, an electric lamp, a circuit therefor, a photo-electric cell having a characteristic responsive to the degree of the total illumination of said surface, an electron tube connected to a source of energy, adjustable means to effect response of said electron tube to the operation of said photo-electric cell, a reversing relay responsive to the current of said tube and provided a mally connected by said relay in parallel with each other, an alternating current motor having a pair of reversing windings, each connected to one of said contacts, an impedance connected in series with said windings across a supply of alternating current, said relay being adapted, upon response thereof, to disconnect one of said reversing windings from circuit to cause said motor to rotate in opposite directions selectively, and a regulator operable by said motor and adapted to vary the voltage impressed upon the circuit of said electric lamp.

3. A control system for controlling the light output of a group of electric lamps to maintain the illumination of a surface illuminated thereby and by an uncontrolled light degree of illumination above a given minimum, comprising, in combination, a group of electric lamps, a circuit therefor, a pair of direct current terminals, a photo-electric cell, a resistance connected in series with said photo-electric cell across said terminals, a thermionic tube having a cathode, an anode and a grid, means to impress upon said grid a voltage of said cell, means to connect said cathode and anode across said terminals and to impress a variable potential upon said cathode, anelectromagnetic relay provided with two opposing windings connected to said terminals, means to impress a potential varying with the voltage between said cathode and anode upon one of said windings, a reversible motor controlled by said relay, and a regulator operable by said motor and adapted to vary the u lumination abov a source to effect ranged to connect one or the voltage impressed upon the circuit or said electric lamps. q

4. A control system for controlling the light output or a group of electric lamps to maintain the illumination of a surface illuminated thereby and by an uncontrolled light source Jointly at a degree of illumination above a given minimum, comprising, in combination, a group or electric lamps, a circuit therefor, a pair of direct current terminals, a photo-electric cell, a resistance connected in series with said photo-electric cell across saidterminals, a thermionic tube having a cathode, an anode and a grid, means to impress upon said grid a voltage of said cell, means to connect said cathode and anode across said terminals and to impress a variable potential upon said cathode, an electromagnetic relay provided with two opposing windings connected to said terminals, means to impress a potential varying with the voltage between said cathode and anode upon one of said windings, a regulator operable by said motor and adapted to vary the voltage impressed upon the circuit of said electric lamps, said relay being also provided with a pair of contacts normally connected together, an alternating current motor having a pair of reversing windings each connected to one of said contacts of said relay, and in impedance connected in series with said windings, said relay being adapted upon response to disconnect one or the other of said reversing windings from circuit to cause said motor to rotate in opposite directions selectively.

5. A control system for a reversing alternating current single-phase motor having a pair of reversing windings, comprising, a condenser, means operable automatically to connect one or the other of said windings in series with said condenser across an alternating current supply circuit for rotation of said motor in opposite directions selectively, and said means being also operable automatically to connect the two windings in parallel with each other and in series with said condenser across said alternating current stopping of the motor.

6. A control system for a reversing alternating current singlehase motor having a pair of reversing windings, an impedance comprising an inductance and a parallel condenser, means arother of said windings in series with said impedance across an alternating current supply circuit for rotation of said motor in opposite directions selectively, and to connect the two windings in parallel with each other and in series with said impedance across source jointly at a l0 versing said alternating current source of the motor.

. '7. A control system for a reversing alternating current single-phase motor having a pair of rewindings, an impedance comprising an ohmic resistance and a condenser connected in parallel therewith, means operable automatically to connect one or the other of said windings in series with said impedance across an alternating current supply circuit for rotation of said motor in opposite directions selectively, and said means being also operable automatically to connect the two windings in parallel with each other and in series with said impedance across said alternating current source to effect stopping of the motor.

to effect stopping 8. A control system for controlling the light output of an electric lamp to maintain the illumithereby and by an degree of ilcomprising,

nation of a surface illuminated uncontrolled light source jointly at a given minimum.

in combination, an electric lamp, a circuit therecomprising, in combination, a group of electric tor, a photo-electric cell having a characteristic lamps, a circuit source of energy, adjustable means to efi'ect reacross said terminals, an electron tube having sponse of said electron tube to'tlie operation of a cathode. an anode and a grid. means to impress said photo-electric cell, a relay responsive to the upon said grid a voltage of said photo-electric circuit to cause the motor to rotate in opposite re ulator including a variable voltage auto-transdirections selectively, and a regulator including f mer operable by s id m tor and apted to a variable voltage auto-transformer operable by Vary the v l ageimpress d p n he circuit oisaid Qutput of an electric lamp to maintain the versing windings each connected to one of said lumination of a surface illuminated thereby and mum; of said relay. d an m nce contal illumination of said surface, an electron tube 01 system comprising. a r v rs ng alconnected to a source of energy. adjustable means ternatmg current i -P 11101101 having a to eilect response of said electron tube to the opreversing Wmdmgs, condenser. means emtmn f said photmelecmc can, a reversing operable automatically to connect one or the other relay responsive t the current of said tube and of said windings in series with said condenser provided with a pair of contacts normally com across an alternatnig current supply circuit for meted by said relay in parallel with each ether, rotation of said motor in opposite directions selecan alternating current motor having a pair of resaid means being Operable t mativerging windings each connected to one of said cally to connect the two windings in parallel with thereof, to disconnect one or the other of said 40 variable Image autotransformer operable by reversing windings from circuit to cause said mo= said motor tor to rotate in o ite directions selective d contr 01 system com-pr using a reversing pm 1y an ternating current single-phase motor having a said mlamp. parallel with the latter, means arranged to con-= m A control System for controlling me light meet one or the other of said windings in series output of a group of el t i lamps to maintain with said impedance across an alternating current the illumination of a surface illuminated thereby Supply circuit 0f Said motor said terminals, an electron tube having a cathode, transformer Operable by said motoran anode and a grid, means to impress upon said i4. control system comprising, a reversing algrid a voltage of said photo-electric cell, means mating "current Single-phase motor having a trolled by said relay, and a regulator including a means being also Operable automatically to convariable voltage auto-transformer operable by said I169? the two windings in Parallel W a ot e motor and adapt-ed to vary the Voltage impressed and in series with said impedance across said alupon th irc it of aid l t i la ternating current source to effect stopping oi the 11. a control system for controlling the light o motor, and a regulator including a variable voltoutput of a group or" electric lamps to maintain age auto-transformer operable by said motor.

the illumination of a surface ill t EDWIN W. SEEGER.

' JURG 5i. SENN.

M-LRROLL STANSBURY. 

